1. Field of the Invention
This invention relates to couplers for attaching trailers to towing vehicles, and in particular to a self-latching coupler which can be locked to prevent theft of a trailer.
2. Description of the Related Art
Various types of trailer couplers have been used to attach a trailer to a towing vehicle. Commonly, a coupler attached to a tongue of the trailer rotatably clamps to a hitch ball on the towing vehicle. Variations on this system are used on both bumper-hitch trailers and “gooseneck” trailers which attach to a ball located in the bed of a truck.
A problem with all trailers (being inherently portable) is that they are relatively easy to steal. A parked trailer may be stolen simply by attaching a suitable towing vehicle and driving off. If the trailer is parked with a towing vehicle attached, the trailer may still be disconnected and then reattached to the thief's vehicle.
In an attempt to prevent such thefts, prior art trailer couplers have often included a hasp for attaching a padlock to lock the coupler in a latched configuration. If a trailer is parked with the coupler locked in the latched position, the trailer cannot be easily hitched to a towing vehicle, and is thus more difficult to steal. Similarly, if the coupler is locked in the latched position while the trailer is attached to a towing vehicle, it becomes more difficult to disconnect it from that towing vehicle. A problem with couplers requiring a padlock, however, is that padlocks are often misplaced or otherwise not available when needed. Furthermore, most padlocks can be fairly easily removed from a trailer coupler using bolt cutters or the like.
Other trailer locks currently in use generally fit around or into a trailer coupler to prevent the trailer from being attached to a towing vehicle. These types of locks must be removed before the trailer is connected and cannot be used on an attached trailer. These locks are also subject to loss when removed from the trailer.
What is needed is a trailer coupler having an integral lock mechanism that cannot be lost or easily defeated using bolt cutters or the like. Such a coupler could be locked in the latched position to prevent theft of the trailer either when the trailer is parked unhitched and unattended, or when the trailer is attached to a towing vehicle.